The transport sector is seen as particularly problematic when concerns about climate change and dependency on fossil energy are discussed. Because of this, bioenergy is strongly promoted for use in the transport sector, both on a European level and nationally in Sweden. Even though bioenergy is considered one of the key solutions, it is generally agreed that both supply- and demand-side measures will be needed to achieve a change to a more sustainable transport system. One of the reasons for this is the limited availability of biomass, especially agricultural feedstocks competing with food or feed production. Woody biomass, however more abundant, is also exposed to tough competition from other sectors. In this thesis, the role of biogas as a vehicle fuel in a future sustainable transport system is discussed together with the prerequisites needed to realise such a transport system. Biogas is a biofuel that could be produced in several different ways: by anaerobic digestion, which is a first-generation production route, by gasification, which is a second-generation process, and by catalytic reduction of carbon dioxide, a third-generation technology. The main focus in this thesis is on biogas produced by anaerobic digestion and the results show that there is a significant potential for an increase compared to today’s production. Biogas from anaerobic digestion, however, will only be able to cover a minor part of the demand in the Swedish transport sector. Considering biogas of the second and third generations, the potential for production is more uncertain in a mid-term future, mainly due to competition for feedstock, the possibility to produce other fuels by these processes, and the present immaturity of the technology. The limited potential for replacing fossil vehicle fuels, either by biogas or other renewable fuels, clearly shows the need for demand-side measures in the transport system as well. This thesis shows the importance of technical and non-technical means to decrease the demand for transport and to make the transport as efficient as possible. The results show that both energy-efficient vehicles and behavioural and infrastructural changes will be required. Policies and economic incentives set by governments and decision-making bodies have a prominent role to play, in order to bring about a shift to a more sustainable transport system, however, measures taken on individual level will also have a great impact to contribute to a more sustainable transport system. / <p>QC 20121116</p>

The aim of this report is to give a picture of how attitudes and behaviours of owners of environment cars look like and how they can be influenced. The alignment lies on environmental cars which run on biogas and ethanol which both are renewable fuels. The starting point is to sort out if it is environmental thinking that controls the choice and use of an environmental car. The feeling is that there are many other factors that can be more controlling, for example the price and the quality of the car. The result of the questionnaire survey which is the foundation of the report shows however that those who buy an environmental car do it mostly because of environmental reasons. Also the daily choice of fuel is mainly environmentally influenced; it however shows that there is dissatisfaction with the high fuel consumption, the short reach and above all the high price of ethanol. It also shows that the source of information which had the biggest impact on the choice to buy an environmental car is the mass media and that the most influencing policy instruments is the price, partly the cheaper on renewable fuel and the more costly fossil fuel. In general the environmental car owners are also positively inclined to using policy instruments of various kinds in order to increase the proportion of environmental cars on our roads. The conclusion becomes thus that the original feeling is incorrect and that environment cars have not at all lost credibility, not anyway on the level that has been investigated in this report. / Syftet med den här rapporten är att gen en bild av hur attityder och beteenden hos ägare av miljöbilar ser ut samt hur de kan påverkas. Inriktningen ligger på miljöbilar drivna med biogas och etanol vilka båda är förnyelsebara bränslen. Utgångspunkten är att reda ut om det är miljötänkandet som styr val och användning av en miljöbil. Känslan är att det finns många andra faktorer som kan vara mer styrande, exempelvis pris och kvalitet på bilen. Resultatet av den enkätundersökning som ligger till grund för rapporten visar dock att de som köper en miljöbil gör det till största delen på grund av miljömässiga orsaker. Även det dagliga valet av bränsle påverkas mestadels av miljömässiga orsaker, det visar sig dock att det finns ett missnöje med den höga bränsleförbrukningen, den korta räckvidden och framförallt det höga priset på etanol. Det visar sig också att den källa till information som haft den största påverkan vid valet att köpa en miljöbil är media samt att det mest påverkande styrmedlet är priset, dels det billigare på förnyelsebara bränslen samt det dyrare på fossila bränslen. Generellt är miljöbilägarna också positivt inställda till att använda styrmedel av olika slag för att öka andelen miljöbilar på vägarna. Slutsatsen blir således att den ursprungliga känslan är felaktig och att miljöbilar inte alls tappat i trovärdighet, i alle fall inte på det plan som granskas i denna rapport.

This thesis consists of four papers: two of them deal with the effects on the forest sector of an increase in the demand for forest fuels, and two of them concern the relation between economic growth and pollution. Paper [I] is a first, preliminary study of the potential effects on the Swedish forest sector of a continuing rise in the use of forest resources as a fuel in energy generation. Sweden has made a commitment that the energy system should be sustainable, i.e., it should be based on renewable resources. However, an increasing use of the forest resources as an energy input could have effects outside the energy sector. We consider this in a static model by estimating a system of demand and supply equations for the four main actors on the Swedish roundwood market; forestry, sawmills, pulpmills and the energy sector. We then calculate the industries' short run supply and demand elasticities. Paper [II], is a development of the former paper. In this paper, we estimate the dynamic effects on the forest sector of an increased demand for forest fuels. This is done by developing a partial adjustment model of the forest sector that enables short, intermediate, and long run price elasticities to be estimated. It is relevant to study the effects of increased demand for forest fuels as the Swedish government has committed to an energy policy that is likely to further increase the use of renewable resources in the Swedish energy system. Four subsectors are included in the model: forestry, sawmills, pulpmills and the energy industry. The results show that the short run elasticities are fairly consistent with earlier studies and that sluggish adjustment in the capital stock is important in determining the intermediate and long run responses. Simulation shows that an increase in the demand for forest fuels has a positive effect on the equilibrium price of all three types of wood, and a negative effect on the equilibrium quantities of sawtimber and pulpwood. In paper [III] a Shephard distance function approach is used to estimate time series of shadow prices for Swedish emissions of CO2, SO2, and VOC for the period 1918 - 1994. The shadow prices are in a next step regressed on GDP per capita. The objective of the study is closely linked to hypothesis of environmental Kuznets curves. We conclude that the time series of the shadow prices from this approach can not be used to explain the EKCs found for Swedish emissions. In paper [IV], we calculate time series of shadow prices for Swedish emissions of CO2, SO2, and VOC for the period 1918 - 1994. The shadow prices are in a next step related to income, to explain the EKCs previously found for Swedish data on the three emissions. Newly constructed historical emission time series enable studying a single country's emission paths through increasing levels of economic activity. A directional distance function approach is used to estimate the industry's production process in order to calculate the opportunity costs of a reduction in the emissions. The time series of the shadow prices show support for EKCs for the Swedish industry.

This thesis follows the process of introducing natural gas in Sweden and the construction of a Northern European gas grid from 1967 to 1991. Natural gas is a relatively unnoticed fuel in Sweden today, but this relative anonymity stands in contrast to an extensive historical activity that has taken place behind the scenes of Swedish energy policy. The single pipeline constructed between Denmark and Sweden in the early 1980s was both preceded and followed by many other attempts to construct a larger natural gas pipeline in the region made in the last 50 years. Åberg traces these attempts while discussing the complex and messy process of constructing and managing a transnational energy infrastructure.Åberg follows actors in Sweden and other countries in their attempts to negotiate and construct a natural gas infrastructure, and puts this process into a national as well as transnational context. The perceived risks and opportunities surrounding natural gas are examined, together with factors that have influenced the development of natural gas in a broader sense. By seeing the changing and messy natural gas projects as arenas where different actors construct and negotiate risks and opportunities, as well as contexualize the projects, Åberg shows how the natural gas sector in Sweden has evolved and taken shape.The study shows that natural gas in Sweden has suffered from unstable actor coalitions on different levels, a difficult market situation, and a changeful political context, especially with regard to energy policy. The import status of the fuel and the consequential transnationality of the natural gas infrastructure have also made the process of constructing a pipeline more complex. However, natural gas was introduced in Sweden, showing that when a strong enough actor coalition agreed that there was enough reason to warrant a natural gas introduction and was ready to join this endeavor, a connection could be achieved. This puts into question to what degree general explanations in terms of finance and policy drive energy decisions, and makes a case for showing how these explanations are adapted into their social and historical contexts in sometimes surprising ways. / <p>QC 20130507</p> / The integration of energy markets across system and nation boundaries

This thesis reports a model to predict the auto-ignition time of single droplets of n-paraffin fuel mixtures using the method of continuous thermodynamics. The model uses experimental data for pure fuels to fit rate parameters for a single-step global chemical reaction equation; from this, correlations for rate parameters as a function of species molecular mass are derived, which are integrated to produce a continuous thermodynamics expression for mixture reaction rate. Experiments were carried out using the suspended droplet-moving furnace technique. The model was then tested and compared to experimental data for three continuous mixtures with known compositions: one ranging from ¬n-octane to n-hexadecane, the second ranging from n-dodecane to n-eicosane, and the third being a combination of the first two mixtures to produce a “dumbbell” mixture. Discrete and continuous mixture models of the ASTM standard distillation test were compared to design the experimental mixtures and provide the distribution parameters of the continuous mixtures intended to simulate them. The results of calculations were found to agree very well with measured ignition times for the mixtures.

This thesis reports a model to predict the auto-ignition time of single droplets of n-paraffin fuel mixtures using the method of continuous thermodynamics. The model uses experimental data for pure fuels to fit rate parameters for a single-step global chemical reaction equation; from this, correlations for rate parameters as a function of species molecular mass are derived, which are integrated to produce a continuous thermodynamics expression for mixture reaction rate. Experiments were carried out using the suspended droplet-moving furnace technique. The model was then tested and compared to experimental data for three continuous mixtures with known compositions: one ranging from ¬n-octane to n-hexadecane, the second ranging from n-dodecane to n-eicosane, and the third being a combination of the first two mixtures to produce a “dumbbell” mixture. Discrete and continuous mixture models of the ASTM standard distillation test were compared to design the experimental mixtures and provide the distribution parameters of the continuous mixtures intended to simulate them. The results of calculations were found to agree very well with measured ignition times for the mixtures.

One of the proposed solutions to the issue of nuclear waste volume is to transition from once through nuclear fuel cycle to advanced fuel cycles with used fuel recycling option. In any advanced fuel cycles with recycling options, the type and amount of separation technology deployed play a crucial role in the overall performance of the fuel cycle. In this work, a scenario study involving two advanced fuel cycles in addition to the once through fuel cycle were evaluated using VISION nuclear fuel cycle simulation code. The advanced fuel cycles were setup to transition completely to full recycling without any light water reactor by assuming all LWR currently in operation will have 20 years of operating life extension and no new LWR will be constructed thereafter. Several different separation capacities (1kT/yr, 2kT/yr and 4 kT/yr) were deployed and the overall impact of these capacities was analyzed in terms of resources utilization, used fuel and waste material generated and the amount of storage space required. Economic parameter (LCOE, LFCC, etc) analysis was also performed using VISION.ECON. Results presented in this work suggest that the need for LWR-UNF storage can be minimized if sufficient separation capacity is deployed early in the fuel cycle. It can also be concluded that a FuRe system without LEU will not be feasible, thus SFRs must be designed for optional use of LEU fuel. Otherwise LWRs must continue to be part of the mix to keep the near term cost of generating electricity competitive. It was observed that the higher amount of separation capacity deployed in the advanced fuel cycles led to higher LFCC and LCOE, but also translates into less environmental impact on both front and back end of the fuel cycle.

The Environmental Kuznets Curve is an inverted U-shaped relationship which demonstrates how environmental degradation increases as countries begin to develop and lowers as they become wealthier. The classical EKC measures the effects of GDP per capita (a country’s wealth) on pollu-tion. This paper is a study of the connection of a number of factors- GDP per capita, fossil fuels, al-ternative and nuclear energy, rural population and life expectancy at birth to the Environmental Kuznets Curve. Two econometric approaches are applied in order to test whether the variables have a more pronounced linear or quadratic form. Four income groups of countries are investigated in order to check if the state of development plays a crucial role in environmental deterioration. The results of the study point out that EKC does not apply for the chosen variables. From the regression for GDP, however, it can be concluded that EKC forms in 1990s.

The dependency on fossil fuels faces resource limitations and sustainability concerns. This situation requires new strategies for greenhouse gas emission management and the development of new sources of energy. This thesis explores fundamental concepts related to carbon geological storage, including CO2-CH4 replacement in hydrate-bearing sediments. In particular it addresses the following phenomena: - Interfacial tension and contact angle in CO2-water-mineral and CH4-water-mineral systems. These data are needed to upscale pore phenomena through the sediment porous network, to define multiphase flow characteristics in enhanced gas recovery operations, and to optimize the injection and storage CO2 in geological formations. - Coupled processes and potential geomechanical implications associated to CH4-CO2 replacement in hydrate bearing sediments. Results include physical monitoring data gathered for CH4 hydrate-bearing sediments during and after CO2 injection. - Performance of cap rocks as trapping structures for CO2 injection sites. This study focuses on clay-CO2-water systems and CO2 breakthrough through highly compacted fine-grained sediments. Long term experiments help evaluate different sediments according to their vulnerability to CO2, predict the likelihood and time-scale of breakthrough, and estimate consequent CO2 leaks.

Thesis (Ph.D.)--Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.